E30 M3 coolant expansion tank work with M20?

[E30-Ellerman]

Hey there, sorry if this has been discussed just couldn't find it in search.

Have a pre facelift E30 that I will be turbo'ing in the near future. Need to relocate the coolant reservoir tank and have a line on a cheap M3 coolant tank that mounts near the firewall on passenger side.

Wondering if this tank will 1) bolt up easily in the battery tray area near the firewall on passenger side (where it bolts into the m3) and 2) if the hoses will work with the water pump and radiator (same size hosing?)

Have others done this and I just can't find it in my searching?

Thank you!

[reelizmpro]

I don't see why not as long as you extend the hoses since both tanks are on the same side of the engine. The M3 tank will just be farther away. I think the later style tank would be better though.

[E30-Ellerman]

Thanks man, same thing I was thinking, would get longer hoses and everything, would hide it away from the turbo and from an M3 engine bay, looks far enough away from the turbo exhaust housing to be fine.

[reelizmpro]

Is it a top mount turbo? if so, the downpipe will be in the way of the coolant hose. With the late model setup it keeps the coolant hoses on the drivers side away from the heat.

[E30-Ellerman]

Yes it will be a top mount turbo... thinking it may be easier to relocate stock one as it's smaller (oval/pill shaped one), only tough part is making brackets to mount in battery tray area..

[AndrewBird]

Is it a top mount turbo? if so, the downpipe will be in the way of the coolant hose. With the late model setup it keeps the coolant hoses on the drivers side away from the heat.

I'd do this and swap to a late model system. All factory parts that are proven to work.